Americans have mixed views on several aspects of the shooting incident at the Army installation in Fort Hood, Tex. — including whether or not it should be called an act of terrorism.

A Fox News poll released Friday finds nearly half of the public — 49 percent — think the shooting is most accurately described as "a killing spree." Almost as many — 44 percent — say the incident should be called an "act of terrorism."

Click here to see the poll.

Among groups, young people under age 35 see it as a killing spree (61 percent), but seniors 65 and over are more likely to describe it as terrorism (57 percent). Democrats are more likely to call it a killing spree (63 percent), while Republicans tend to call it terrorism (58 percent). Men divide evenly between the two descriptions, while a majority of women say the shooting was a killing spree (53 percent) rather than terrorism (41 percent).

Officials say Army Major Nidal Hasan was the gunman behind the deadly November 5 shootings. Thirteen people were killed and 29 others were wounded.

Asked about Hasan's possible motive for the shooting, 45 percent think he is someone who just went nuts one day and opened fire, while 38 percent think he is a Muslim extremist protesting U.S. foreign policy. One in 10 thinks it was some of both.

Opinion Dynamics Corp. conducted the national telephone poll of 900 registered voters for Fox News from November 17 to November 18. For the total sample, the poll has a margin of error of plus or minus 3 percentage points.

Several colleagues and acquaintances of Hasan now say they had concerns about him in the past. Americans think the main reason these people kept silent was political correctness: 46 percent think Hasan's co-workers did nothing, even though they thought something was wrong, because they feared being accused of prejudice against his religion. Some 38 percent say people kept silent because they didn't think he was that dangerous (38 percent).

Majorities of Republicans (60 percent) and independents (52 percent) blame the silence on political correctness. For Democrats, a majority says the main reason people kept quiet was they didn't think Hasan was dangerous (54 percent).